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What Is a CAL, and How Many Do I Need?

What Is a CAL, and How Many Do I Need?

For any business with networked workstations, network server software is required to perform certain tasks such as file sharing, collaborating, printing and more. Accessing this server software requires users to have a license, which is where things can get really complicated.

Even for the most seasoned IT professionals, deciphering Microsoft licensing and the client access license (CAL) puzzle can be a real challenge. Sometimes it feels like CALs are the dark matter of the Microsoft universe. They can’t be seen, counted or quantified, but they carry a lot of weight when it comes to your budget and how the workstations in your organization are networked.

For many IT departments, choosing the right licensing option and finding the best deal is confusing. For most businesses, CALs are required. But once you have determined you need them — how many CALs, exactly, do you need?

What Is a CAL?
A CAL is a license that grants access to specific Microsoft Server software. CALs are used together with Microsoft Server software licenses to allow users and devices to access and use services.

There are four main types of CALs: User CALs, Device CALs, Terminal Services and Remote Desktop Services.

A User CAL allows a single unique user to access Microsoft Server software from multiple devices including a desktop computer, laptop, handheld device and more without having to purchase a separate CAL for each device. This is ideal for businesses with employees who access the corporate network through multiple devices or those with more devices than users in the organization.

With a Device CAL, any number of physical users can access Microsoft Server software through a single device. In other words, you would purchase a single CAL for every device that accesses the server, no matter how many people use that device on a daily basis. This licensing model makes the most sense for companies who have employees sharing devices, often on different shifts or at different times throughout the day.

Terminal Services provide remote access to a server desktop through terminal emulation software. This software can run on multiple client hardware devices and sends keystrokes and mouse movements to the server, allowing remote control of servers and centralized application management. Network bandwidth requirements between the client and server are also minimized. With terminal services, network resources can be managed remotely and multiple users in branch offices and remote locations can easily gain access.

Remote Desktop Services (RDS) provide a virtual platform with secure mobile and remote desktop access that enables users to run their applications and desktops from the cloud. An RDS solution can be set up for session-based virtualization, as a virtual desktop or even as a combination of the two. With Remote Desktop Services, you can remotely, securely and cost effectively deploy the desktops and applications that your users need.

Two rarer types of CALs are External Connector (EC) and Processor licenses. EC licenses enable users outside your organization to access your company network on a limited basis. Processor licenses are only available for certain Microsoft Server products and provides access for an unlimited number of users who can connect from either inside your local area network (LAN), wide area network (WAN) or outside the firewall.

How Many CALs Do I Need?
Once you know you need CALs for the users in your network, the next question is how many CALs do you need? Think of it like this: a server CAL provides users with the right to connect to and use your server as a resource. A “user” is defined as a physical person covered by one User CAL.

If your office has one server and 20 individuals connect to it to share files, print and use other services, you would need a server license plus 20 CALs to allow everyone to connect legally. Every user who accesses your server in any way needs a CAL.

CALs are, however, per user — not per user and per server. Only one CAL is needed for every user on your network for the highest-level server you own. As your network and number of users grow, you can add CALs as you go.

Even if a user logs on to the server with multiple different login names, that user is still just one physical person and considered a single user, so only one User CAL is required. It doesn’t matter how many machines or devices he accesses or how many logins he uses, each unique person is still counted as one user.

Remember: CALs are required even if users are not Windows based. A Linux desktop using file or print services would still need a CAL, for example. That said, a Windows server CAL is not the same as a desktop operating system license. An independent user using a Windows PC, for example — who is not sharing a network with other users — has a Windows client license associated with his or her machine, such as Windows 10 Pro with Windows Server 2012 R2 Standard.

Want to learn more about CALs and Microsoft licensing options? Our experts can help you find the software licensing package that is the best fit for your organization. Call us today at 1-855-AVENTIS.